In a March 23 column on the Wall Street Journal's OpinionJournal.com website, Journal editorial writer Stephen Moore claimed that the Preble's meadow jumping mouse -- a small rodent native to Colorado that was placed on the U.S. Fish and Wildlife Service's “Threatened” list in 1998 -- is “not endangered” and “isn't even a unique species.” Moore cited a 2003 study conducted by former Denver Museum of Nature and Science curator Rob Roy Ramey, which found that the mouse “is not a valid subspecies based on physical features and genetics.” According to Moore, Ramey “expos[ed] the truth about the Preble's mouse.” However, a more recent and more exhaustive study conducted by the U.S. Geological Survey (USGS) found that Preble's meadow jumping mouse is, in fact, a distinct subspecies, qualified for protected status under the Endangered Species Act.

In his OpinionJournal.com column, Moore wrote:

What we have here is arguably the most contentious dispute over the economic impact of the ESA since the famous early-'90s clash between the timber industry and the environmentalist lobby over the “endangered” listing of the spotted owl in the Northwest. That dispute eventually forced the closure of nearly 200 mills and the loss of thousands of jobs. Last week the war over the fate of the Preble's mouse escalated when a coalition of enraged homeowners, developers and farmers petitioned the Department of the Interior to have the mouse immediately delisted as “endangered” because of reliance on faulty data.

The property-rights coalition would seem to have a fairly persuasive case based on the latest research on the mouse. It turns out that not only is the mouse not endangered, but it isn't even a unique species.

The man who is almost singlehandedly responsible for exposing the truth about the Preble's mouse is Rob Roy Ramey, a biologist and lifelong conservationist, who used to serve as a curator at the Denver Museum of Nature and Science. Mr. Ramey's research -- published last year in the peer-reviewed journal Animal Conservation -- concluded that the Preble's mouse “is not a valid subspecies based on physical features and genetics.” The scientist who conducted the original research classifying Preble's as unique now agrees with Mr. Ramey's assessment. Even scientists who defend extending the mouse's “endangered” status admit that it is 99.5% genetically similar to other strains of mice.

Nor is the mouse on the road to extinction. “The more people look for these mice, the more they find. Every time scientists do a new count, we find more of the Preble's mouse,” Mr. Ramey says. It's now been found inhabiting twice as many distinct areas as once thought. These are mice, after all, and the one thing rodents are proficient at is breeding. The full species of the meadow jumping mouse, far from being rare, can be found over half the land area of North America.

Moore made no mention of the USGS study, the findings of which were released in January (belying his claim that Ramey's study represented the “latest research”). According to a January 25 Rocky Mountain News article, the USGS study “rejects previous findings and concludes that the Colorado-dwelling rodent is a distinct subspecies.” The Rocky Mountain News also noted that the USGS study was more exhaustive than Ramey's study:

But behind the scenes, U.S. Geological Survey scientists were taking a closer look at the genetic makeup of the Preble's mouse. The team, headed by Tim King, studied more genes and examined more individual mice than Ramey did, said Eric Hallerman, a professor of fisheries and wildlife sciences at Virginia Tech University.

“This study found that the Preble's jumping mouse is a valid subspecies. And the implication is that if it's a valid subspecies, it may be protected under the ESA,” said Hallerman, who has read the King study.

“When I looked at the Ramey study, I had lots of criticisms,” Hallerman said. “When I look at the King study, my sense is, 'I wish I had done that work.' It's nicely done.”

Ramey was traveling in Mexico on Tuesday and could not be reached for comment.

“One of the problems with the Ramey study is he didn't collect very much data, so his inferences about biology weren't very robust,” said Andrew Martin, a University of Colorado biologist.

“Whereas the King group, they collected a lot of data -- an enormous amount of data -- and then did the analysis very objectively.”

Additionally, the fact that Preble's mouse “isn't even a unique species,” as Moore wrote, is irrelevant. An organism can be classified as a subspecies and qualify for protection under the Endangered Species Act. The act 000-.html">explicitly states that the term “species” includes “any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature.” “Species” is a category of biological taxonomy that consists of related organisms that are capable of successfully breeding among themselves, but not with individuals of a separate species. “Subspecies” is a subdivision of that category. For example, the meadow jumping mouse is classified zapus hudsonius. Preble's meadow jumping mouse -- classified zapus hudsonius preblei, with "preblei" indicating that it is a subspecies -- would be distinct from the Black Hills meadow jumping mouse -- classified zapus hudsonius campestris.